Process of making diolefins.



mil; a (le g all :is more :is Claimed.

' are (loiilily iniances liei'iiig loinst xi readdiere au acecenunercril 'ne iiseri.

sli :DEVELOPMENT .Y tliese materials are all relanfl die presentVprocesses of not only laborious and eX- iii` t:ive low )viel-cls ofdielens. methods (lo noty clireeliv produce sucli l3nt `eiie compoundsioleins iniisl lie recovered; .the use of lialogens, orclina v ii tlieoperation. i expensive iiliile its 1, necessitating the use oiints innialiing relaunts of cliolens. l L of the present invention to i acheap, simple and ready v using pel'releuin or perolcuin procla rau' maand directly isolating recovering Ulie iliolelins as such in lieucostly, prorlucion are subsequenly decomposed to obtain leaiy petroleumoils, such eriides. gas oils, paral'lin oils, lubrinii lei-nisa ai i featin@ i still residues and tlie like are paricul suitable for nu;purpose since they censisi mainly of liji'ilroczirlions of coinpareifelyliigli molecular Weight which give nie eel-ter c, and are also cheaper.Even solid paralnm and peroleiiui waxes may be used. F find liat oilsboiling l10U L Y lil lo 2O :ire lies' suited. Lower boiling suitablelint may, in some inlie utilized for nig.'v purposes. lt is inlog' oilsal, least relatiif'elj.'v free or areniatic compounds which-`roncliiiens of my process. would lienzehl eliieue, etc.; bodies whichand consisting niaiiil7 of 'ein ilie fliolefins and ii'liicli. in im 'iV`o lieir auieiinh iliniiiiisli the yield :l ins. iifler licconditionsof Jflie )recess cjfi'lic lij-rilrecarbons are not forni-eil f7@ 'new'lo any substantial eXtent. Gas elle and lubricating Oils ii'liicli areperoleiiin oilsI freed o'l-lmv boiling conslitugaselene. kerosene and,in sonic oils` are particularly well purposes. Spindle oilsl may at bysiibieciing *Clie perolieniperani'e and a gasifia liniizecl butappreciable s are e'rinel. The formation results 'ilian low-boilingliyflroployed however 'aries with other circum- AIl() stances; and withplenty ot' oil vaporsa` enough to insure that with the proper time ofdiolefin formation given there shall still be unchanged oil vapors andolefin gases in the sphere of reaction, the temperature may even bepushed up to a white heat. lVith a copious oil feed, I have lnade gascontaining nearly 8 per centdiolefins in a tube nearlv white hot. Butthe gas carrying the dioletins and made at this high heat is not so wellsuited, after isola tion and recovery ot the diolefins, for theproduction of more diolefins in the manner hereinafter described. Thehigh heat damages the gas carrying' the diolefins. I lind temperaturesaround 700C with 800Q C. as a maximum and 600O C. as`

a minimum are best adapted to my pulpOSQS. The time factor is animportant one since the diolefins are zuaparentl)Y formed by seeondaryreactions at the expense ot the gases directly formed from the oil; andthese sec- -ondary reactions yrequire an appreciable time. Theirvelocity appears to follow however a descending curve. As a rule, theheating should be continued until the per cent. ot dioletins in thegases ceases to, increase rapidly and thenv the gases should be at oncecooled to arrest further internal reactions. In passing the vapors andgases' through a narrow hot tube, I nd that with about 2 secondsexposure to heat l can se cure a gis containing` 4 to 5 per cent. of.dioletins while by heating for 5 seconds, I cansecvne somewhat inexcess of 8 per cent.

' I haveobtained as'higrhl as l1 per cent. with 30 seconds exposure; butordinarily I find, and particularly where the gas is to be used again tomake more diolefins (as "hereinaftcr described), it better to'ceaseheating when the diolefins are around 8 per cent.

Expressed in terms of apparat-us, I find that with a copious feed ofheavy oil, enough to cause unchanged vapors to go past the heatingzone,as little as 6 inches of travel through a narrow heated metal tube atabout 700O C. will cause production of a substantial amount ot'diolefins,.up to i or 5 per cent., in the resulting gas. There-is how'-ever not a great amount of oil converted into gas in the time ofexposure to the gasitying heat. This gas is, roughly, about half olevtins (with a predominating amount of ethylene) and something less thanhalt' ethane.

Vith 30 inches of travel, there is more gas formed, but the per cent. otdiolefins in the gas does not increase materially, vthough the totalamount of gas. and therefore ot dioletins, 1s greater. With 90 inchesot' travel cation.. torts, such as quarter inch and halt inch iai) .maybe made, but I lind'it best to use nar.-

rovv metal tubes, say vbetween l and inch 75 internal diameter.` Thesetubes should be in straight lengths With end'caps'to enable readycleaning bya 'cleaning rod. Contained catalysts and contact masses arenot necessary for successful operation and their presence renders ithard to keep narrow tubes clean and unobstructed. Should hard cokycarbon once form'in the tubes, 'the reg-A ularity of operation isaffected and the tubes quickly plug up, the carbon apparently acting asa. catalytic to form more carbon. Y l/Vith such carbon forming' theoperation is therefore best interrupted at once to remove the carbon.With proper temperatures and care in operation the tube may' go forWeeks 9B Without cleaning.

As many tubes or tube retortsmay be employed operating in parallel asmay be desired; it being better to gain capacity in this Way rather thanby increasingv the di--esameter of the tubes.

Ordinary steel or-iron tubes are suitable, though bronze, brass, copper,aluminum, terracotta, quartz, etc., muy be used. f

The manner of introducing the oil `into loof the tube is not a matteror" indilerence. lVhile vapors may be generated in a special still andsent thence into the tubev retorts it is better to introduce the oil assuch' with a sort ofilooding feed. 0n the rapid supply of oil into thehot tube, a small amount of oil is so quickly vaporiee-' that itdisruptively atomizes the rest and carries the atomized material alongthe tube in a'rapid current. It is not merely the low boiling pertionsthat are so flashed into vapor, the po'rization taking place so rapidlythat all the components of the affected portion ot an oil drop arevaporized. This atomization results in 'carrying mist/ed unchanged iinoil as such through a long space of the heatlli) ed zone and therebycontributes materi: I to the 1uniformity of the results in the The useot'small diameter tube re'- iron piping, aids materially in preservingYthe uniformity of admixture of oil and va pors thus obtained since'thereis no oppotunity for stratication of the heavy oil and oil vapors' and.of the relatively light gas in such small bore tubes; Lew boiling`petroleum oils, aside from not giving as goed results for other reasons,do not permit the described type of atoinization.

Some crude oils on .aporrzation give a Texas crude sold as nav fuel oilsGave good results. All these oils with the del scribed reheating of thegas and with apy desirable.'

paratus of the type described vwill give a yield of total diolefinsamounting to about a quarter their weight. The residue appears as gas ofgood quality for heating and lighting, there being no waste as carbonand tar.

The gas may be used for enriching lean`- gases such as blue gas, watergas, producer gas,'etc. v

In the oil-treating step, the excess of oil going through the heatedtube and afterward condensed is simply returned for repassage togetherwith fresh oil. to around 700 C. and with 'heavy oils, about a quarterof the condensed material will be cracked oil, of the nature of'asolene, kerosene, etc., and the residue will e original oil. In theoperation it is best tohave an oil feed copious enough to insure atleast 10 per cent. of the amount fed in going on past the heating zoneand recoverable on cooling the emerging gasv and vapor current. A largeramount, up to 30 per cent., is often This detail however dependssomewhat on the nature of the heating apparatus. The more accurately andiuniformly the heating operation can be conducted, t-he less is the needfor large ,quantities of shielding oil going forward with the gases. Byrunning the excess of heavy oil through and condensing it rather warm,it will not hold back dioleins. This warm condensation is of course notpossible where the material used is low boiling oils.

Any desired heating means may be ein` ployed, such as electric heating,coal' heating, oil heating, gas heating, etc. Anthracite coal gives auniform type of heating which can be nicely regulated at about the rangeof temperature desired in the present invention. But as the processproduces eon-v siderable residual gas, this may be con-v veniently used.It is however a gas off, desirable character and may be replaced by acheapergas, such as producer gas.

In the reheating of .the oleinic gas to i produce successive crops ofdiolefins it is not necessary vto have oil vapors in the sphere ofreaction and their use introduces practlcal complications 1n theoperat1on. Except 1n theoriginal formation of the gas .therefore Iordinarily do not heat in the presence of oil vapors. `'In thereheating, the tempera# tures may advantageously be, as in the originalproduction of the gas, around 700-C.

. In the original heating of the oil vapors, if desired a diluent gasmay be used. This diluent gas may be residual gas from the- With tubesheated atmospheric pressure.

lute amount. It is not ordinarily desirable inthe speciic embodiments ofmy invention herein described to use air or oxygen. WhereoXidizingbodies are present in the sphere of reaction, the reactions are not 'ofthe simple type 0f thermolyti'c and thermosynthetic desired. in thepresent linvention. Such oxidizing bodies may be used but the reactionsareof somewhat di'erent type.

Diluent gases where used are -more advantageous in the reheating of thegases than in the treatment of the original oil, as the oil vaporsthemselves form a diluent; and a diluent which is particularlyconvenient for the presentpurposes since it may be removed by simplecooling and condensation.

The pressure .under which the operation is carried on may convenientlybe the ordinary Small increases or diminutions of pressure ldo notmaterially change the results and are not particularly;

'vertical section, some parts being in elevation, a typical organizationof apparatus elements within the present invention and useful vin theoperation of the described proc l ess. In this showing, i

Element 1 is a suitable f nrnace chamber. In this chamber are, as shown,four banks, A, B, C, and D,`of tube retorts, the retorts of A serving totransform oil into gas containing oleins and'diolefins and those of B,C, and D being reheaters, or diolefin generators. In each bank, theremaybev as many sets of tube retorts operating in parallel as may bedesired. The tube retorts, as shown,

in all the banks are similar andconsist ef a lengthl 3l of narrowtubi'ig from 0.251130 l inc-h internal diameter connected with anotherlength ir-return tube 4 by vertical connection 5. Each length may havean eXtension of 40 vorj50 inches within thel furnace ohamberQsCaps 6 and'7 at the eitds of each tube enable a cleaning rod to befthrust through.i

Oil is supplied from 'reservoir 8 by means offpump 9 to main .10 whichmay feedany number of tube vretorts operating in parallel in bank A. Thevconnection between,` the main and each tube retort is valvedfat il,

permitting any individual tube retortt'o -be out out for' cleaningwithout interrupting tube retorts are, as shown, best-.supplied with'.i'egulated 1n this event, the still just described (56) .is not used.Brineor calcium chlorid may chilled in'refrigerator 60 and sent by pump5 Chiller (55) and the successive gas chillers hack to :therefrigerator. y

it is-'a luseful expedient in promoting uniformity in the as'es Withinthe tubes andv preventing 'strati cation, to give the tubes a tivist orrifle thereby causing a Whirling motion inthe current passing through atube. The' diolefins recovered in the described operations may befractionated to produce pure erythr'ene, isoprene, piperylene, etc.,orthe inixturemay be; used directly for making mixed caoutchoucs, etc.The diolefins Vproducedin the-oil-gas making operation if containinglight crackedA gasolenes, 2O benzol, etc., may of 'course be separatedfrom these impurities. by fractionation.

W'hat Lolaim is l. In the manufacture of' dioleins, the process whichcomprises removing diolefins 25, from a gas containing oletins,

saturated hydrocarbon gases, While leaving most of the other gasestherein', andv heating the remaining gas under ,such regulatedconditions as to produce a further quantity of dioleins and aconcomitant reduction of the oiefins present.

2. In the manufacture of diolefins, the

AVprocess Whichcomprises heating oil under' *such regulated conditionsas to produce a gas rich in oleins anddiolens and comprising a notablequantity of saturated hy- "drocarbon gas, removing the -diolens, ande'heat'ing the remaining -gas under such vconditions as to produce afurto ther quantity of diolens and a concomitant reduction o f the olenspresent.

TQ3. In the' manufacturel of diolens, the process which comprises.heating oil vapors in transit .to a temperature around 700 C. 5vtillthe quantity of diolefins produced ceases to 'increase rapidly,removing residual .oil vapors from the gas produced, removing iioleiinswhile leaving the principal part of the oleins in the gas, and thenreheating i0 `the remaining gas under such regulated conditions as toproduce further quantity of diolens. el. In the treatment of gases richin un- ,Saturated hydrocarbons including in part ydioleins andfin partother unsaturated hydrocarbons, the process which comprises freeing sucha gas of dioleins While leaving a large part of the' other unsaturatedhydrocarbons and reheating the remaining gas under such regulatedconditions as to produce a further quantity of dioleins and aconcomitant reduction of other unsaturated hydrocarbons present.

5. In the treatment of gases rich in u-n' .65 saturated 'hydi9carbons,including in part (51 and conduit 62 through the oil' vdioleins and.

in it a large part of the other unsaturated hydrocarbons, andreheating-the remaining gas under such regulated conditions as toAproduce a further quantity of dioleiins and a concomitant reduction ofthe other unsaturated hydrocarbons present, these-.operv ations beingrepeated until vsubstantial quantities of 6. The process of producingdiolens which comprises submitting gas :oil to a.

temperature around 7 00o C. to produce various hydrocarbon gases tillvthe quantity of diolefins in the gas produced becomes substantial,cooling to remove residual oil,

removing -the diolefins While leaving most of the other hydrocarbons inthe gas and reheating the remaining gas to produce a further quantity ofdiolefins.

7. The process of producing dioietins which comprises passing` gas oilvapors through ahot narrow tube till the quantity of diolefins in thegas produced approximates` 8 per cent., cooling to remove residual oil,removing the dioleiins and reheating the remaining gas to produce afurther quantity .of diolefins. .f

S. The process of producing dioleiins which 'comprises passing thevapors of a heavy petroleum oil through a hot narrow tube till thequantity of dioleins in the gas produced approximates 8 per cent.,cooling to remove residual oil, removing thediolefins and reheating theremaining gas to produce a furthergquantity of diolefins.

diolefins are no longer formed.

9. In the production of dioleins, the. process which comprises producinggas rich in diolefiii's from petroleum oil, removing such dioleins inthe form of diolei'ins, and heating the remaining gas to produce afurther quantity of diolefins. v 10. In the production. of diolefins,the process which comprisesl producing gas rich in ldioleins frompetroleum oil, removing` such dioleins in the form of diolens, and iheating the remaining gas to a temperature around 700" C. to produce afurther quantity of dioleins.

11. In the manufacture of ,dioleins the processwhich comprises producingan oil gas rich'in dioleins, removing condensable oils therefrom,scrubbing' with chilled oil to remove diolefin's, he ating the remaininggas to produce .a further quantity of 'diolefins and repeating thescrubbing with chilled oil to recover such further quantity.

12. The process of making dioleins which comprises subjecting gascontaining oleins and other hydrocarbons to repeated passages through ahot tube with the temperature. adjusted to produce dioletns andconcomitantly reduce" the oleins, the dioleins produced in each suchpassage *being re- 1H of Said 65 @Notation of mpact with v. amper rt 0unk 1 'il the @Uli bu he n HD5 did@ MERSERE U,

@AEL

N E. SIGGERS, VCELROY.

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